Paratek’s omadacycline sails through AdComm en route to October nod

Omadacycline is the first in a new class of broad-spectrum antibiotics known as aminomethylcyclines, which are structurally related to the commonly used class of tetracycline-based treatments. (FDA)

An FDA advisory committee voted on Thursday to recommend approval of Paratek’s new antibiotic, omadacycline, for the treatment of acute bacterial skin infections and community-acquired bacterial pneumonia (CABP). The agency is expected to make a decision on omadacycline in early October.

The Antimicrobials Drug Advisory Committee voted 17-1 in favor of intravenous and oral omadacycline for the treatment of acute bacterial skin and skin structure infections (ABSSSI) and 14-4 for its use in CABP. Omadacycline is the first in a new class of broad-spectrum antibiotics known as aminomethylcyclines, which are structurally related to the commonly used class of tetracycline-based treatments. It is designed to surmount certain forms of antibiotic resistance found in community-acquired infections, Paratek says.

“[With] once-daily dosing and bioequivalent IV and oral formulations, omadacycline may help facilitate early discharge from the hospital or, in other cases, allow for safe and effective treatment in the outpatient setting,” said Paratek CEO Michael Bigham in a statement. “Today’s recommendations from the Advisory Committee move us one step closer to making this important new treatment option available to patients and physicians.”

Among the data the advisory committee reviewed were the results of three phase 3 studies testing once-daily IV and oral forms of omadacycline in ABSSSI and CABP. The drug met all of its primary and secondary endpoints in all three studies, the company said.

In briefing documents released ahead of the advisory committee meeting, FDA reviewers deemed omadacycline noninferior to moxifloxacin and linezolid, but highlighted the number of deaths in the study testing the med in CABP.

“An important safety concern is the imbalance in 30-day all-cause mortality observed in the CABP trial, with eight deaths in the omadacycline arm compared to three deaths in the control arm,” they wrote (PDF).

“Although the rate of mortality in the omadacycline group appears to be similar to the 30-day mortality observed in recently conducted CABP trials, this mortality imbalance in a randomized controlled trial is noteworthy,” they said.

Four of the eight deaths were linked to cardiovascular outcomes, but the FDA says omadacycline does not appear to carry risks of causing an arrhythmia, and the reviewers said they couldn’t pinpoint the exact cause from the available data.